I can't tell you how to light something; but I can say that I light it for what I and the director feel is appropriate for the film and the scene and the situation. Sometimes that'll be 3 point, often times it won't-- depends on the film and what you want to convey with it, with the scene, with the shot, and then what you've established or intend to establish through the rest of the film. The hows, as in how we get there, is what makes each DoP different, just as directors aren't the same.

don't make the mistake of thinking three-point lighting is some kind of formula and then ignoring it out of rebelliousness. Everyone does this (I did), and then you go around in a big circle and end up doing three-point lighting anyway. Even People that SAY they dont use it, are using it, whether they call it three-point or not. WHy?

Cause its common sense:

You need a light in order to light something. You know, so you can see it. That's your main light. Your "key" light.

Maybe the shadows made by your light are too dark for the look what you want? Gee, maybe Ill add another light to lighten them up. Fill.

Wow, The guys hair is dark and the background is dark and hes getting lost in the scene? Gee. If I hit em from behind with a light he'll pop out. Backlight.

Sometimes you'll use only a key. Some you won't use a backlight. Sometimes you'll use only a key and backlight. Some DPs get all philosophical and never use backlight cause they say it's fake (movies are fake, btw).

Learn three point lighting- think of it as a way to -explain- light sources not so much a technique...

Basically it's how hard or soft your key light is and which direction it's coming from. With a very soft key light, "with wrap around" you may not need any fill. At a certain point your key light could be a back light, but it's still the main lighting source.